Can't tell the exact age as your thumb is covering the serial #. Probably form the late 50s early 60s, unless that is a replacement stock in which case the barrel and receiver could date earlier. It does not appear that that is a switch barrel, so if you want to get another barrel for it down the road it will require a gunsmith, but poly chokes usually pattern pretty well. As for the price I know you could get one cheaper on one of the auction sites, but then you have to add shipping and FFL transfers so it would probably end up becoming a wash, $350 is not a steal, nor are you getting robbed, its just about the high end of the market value on this configuration. If you can haggle with the seller.